When using relatively thick samples (i.e. with a thickness of the order of 0.1 mm) in particle-optical devices such as electron microscopes, one can be confronted with the problem that the details to be studied in the sample are located on the interior of the material of the sample. Such a situation can, for example, arise when using a bacterium as a sample, whereby one would like to subject a detail to further analysis using a (much) stronger magnification in the electron microscope. The device user may suspect that a detail that is of possible interest is situated at a given location on the interior of the sample, but this detail is buried in the bulk of the material and is thus out of the reach of electron-optical imagery using, for example, a Scanning Electron Microscope (SEM). One could conceive, in a separate operation outside the electron microscope, attempting to open up the sample in such a manner that the detail of interest becomes exposed, but, because the detail involved is often smaller than the wavelength of visible light, the processing thereof is obscured from direct observation by the person performing the processing, so that, in the exposure attempt, the detail of interest can easily be missed, or exposed in an undesirable manner. Moreover, it is extremely difficult, and often impossible, to find the right location in which to make a cross-section.